Sacrificial Catalyst Polycrystalline Diamond Element

ABSTRACT

A superhard composite material comprising a polycrystalline diamond cutter (PDC) having a cutting surface and cutting edges having a polycrystalline diamond thickness of about 3 mm is integrally formed with a sacrificial catalyst source that is removed later in the processing of the of the cutter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Disclosed herein are elements of superhard polycrystalline materialsynthesized in a high-temperature, high-pressure process and used forwear, cutting, drawing, and other applications. These elements havespecifically placed superhard surfaces at locations where wearresistance is required. In particular, these elements arepolycrystalline diamond and polycrystalline diamond-like (collectivelycalled PCD) elements with tailored wear and impact resistance andmethods of manufacturing them.

2. Description of the Related Art

U.S. Pat. No. 4,534,773 discloses a method of producing an abrasive bodyof diamond particles in diamond-to-diamond bond with second phase of Niand/or Si under condition of a High Temperature, High Pressure (HPHT)apparatus.

U.S. Pat. No. 6,861,098 discloses known methods for fabrication of PDCcutter, inserts and tools. Polycrystalline diamond and polycrystallinediamond-like elements are known, for the purposes of this specification,as PCD elements. PCD elements are formed from carbon based materialswith exceptionally short inter-atomic distances between neighboringatoms.

One type of polycrystalline diamond-like material is known ascarbonitride (CN) described in U.S. Pat. No. 5,776,615. Another, morecommonly used form of PCD is described in more detail below. In general,PCD elements are formed from a mix of materials processed underhigh-temperature and high-pressure into a polycrystalline matrix ofinter-bonded superhard diamond crystals. A common trait of PCD elementsis the use of catalyzing materials during their formation, the residuefrom which, often imposes a limit upon the maximum useful operatingtemperature of the element while in service.

A well known, manufactured form of PCD element is a two-layer ormulti-layer PCD element where a facing table of polycrystalline diamondis integrally bonded with a substrate of less hard material, such ascemented tungsten carbide. The PCD element may be in the form of acircular or part-circular tablet, or may be formed into other shapes,suitable for applications such as friction bearings, valve surfaces,indenters, bearing elements, earth boring drill bits and the like. PCDelements of this type may be used in almost any application where a hardabrasive wear and erosion resistant material is required. The substrateof the PCD element may be brazed to a carrier, often also of cementedtungsten carbide. This is a common configuration for PCD's used ascutting elements, for example in fixed cutter or rolling cutter earthboring bits when received in a socket of the drill bit, or when fixed toa post in a machine tool for machining These types of PCD elements aretypically called polycrystalline diamond cutters or PDC's.

PCD elements may be formed by sintering diamond powder with a suitablebinder-catalyzing material in a high-pressure, high-temperature press.One particular method of forming this polycrystalline diamond isdisclosed in U.S. Pat. No. 3,141,746 herein incorporated by referencefor all it discloses. In one common process for manufacturing PCDelements, diamond powder is applied to the surface of a preformedtungsten carbide substrate incorporating cobalt. The assembly is thensubjected to very high temperature and pressure in a press. During thisprocess, cobalt migrates from the substrate into the diamond layer andacts as a binder-catalyzing material, causing the diamond particles tobond to one another with diamond-to-diamond bonding, and also causingthe diamond layer to bond to the substrate.

The completed PCD element has at least one matrix of diamond crystalsbonded to each other with many interstices containing abinder-catalyzing material metal as described above. The diamondcrystals comprise a first continuous matrix of diamond, and theinterstices form a second continuous matrix of interstices containingthe binder-catalyzing material. In addition, there are necessarily arelatively few areas where the diamond to diamond growth hasencapsulated some of the binder-catalyzing material. These “islands” arenot part of the continuous interstitial matrix of binder-catalyzingmaterial.

In one common form, the diamond element constitutes 85% to 95% by volumeand the binder-catalyzing material the other 5% to 15% by volume.Although cobalt is most commonly used as the binder-catalyzing material,any group VIII element, including cobalt, nickel, iron, and alloysthereof, may be employed.

U.S. Pat. No. 7,588,108 describes the fabrication of a high impactresistant tool that has a sintered body of diamond or diamond-likeparticles in a metal matrix bonded to cemented metal carbide substrateat a non planar interface. The catalyst for enabling diamond-diamondsintering is provided by the substrate. Based on known art, the generalmanufacture of a PDC cutter or insert or cutting still typically uses acemented carbide substrate to provide catalyst to aid in the sinteringof the diamond particles.

Published U.S Patent Application No. 2005/0044800, describes the use ofa meltable sealant barrier to cleanse the PDC constituent assembly viavacuum thermal reduction followed by melting the sealant to provide ahermetic seal for the further HTHP processing. The sealing of the canused to process the PDC cutter is required to limit contamination fromthe catalyst from the cemented WC substrate to the un-sintered Diamondparticle bed during HTHP processing. HTHP can assemblies to preventcontamination of the PCD table may also use processes such as EBwelding, as is known for standard production of cutters and inserts.

U.S. Pat. No. 5,127,923 describes an abrasive compact that is subjectedto two distinct HTHP operations, the first operation to produce a PDCcutting element with the use of a solvent catalyst sintering aid, andthe second pressing operation with the use of a non-solvent catalystsintering aid.

U.S. Pat. No. 6,045,440 describes an oriented PDC cutter where formationchips and debris are funneled away from the cutting edge via the use ofraised top surfaces on the PCD. The redirection of the debris isachieved by creation of high and low surfaces on the PCD cuttingsurface. Although not described in detail, in the method used to formthe protrusion on the PCD, it is assumed that the surface texture andgeometry in this case is limited to its ability to extrude/form cansurfaces that are a negative of the desired PCD front face extrusions;alternatively post HTHP processing such as EDM and Laser cutting may benecessary to form these surfaces on the cutter face. The geometries inthis case are limited to the protruding feature size, pattern anddistribution. The art is, in general, silent about the use ofsacrificial substrates to generate such surfaces on the as formed PCDtable.

BRIEF SUMMARY OF THE INVENTION

A super hard material composite is described which has an in-situ formedPCD complex face optimized for aggressive cutting of formation, lowcontamination levels in the PCD working surface, and an integrallybonded substrate that can be optimized for wear and impact strength. Thecomposite material has a plurality of hard-phase (Diamond, CBN)particles integrally bonded to plurality of catalyst-free (W, Mo, V,etc) C particles via temperature and pressure. Sintering anddensification of the composite layer is aided by catalyst which may beone or more of Co, Ni, and Fe. These elements may be released from asacrificial substrate that is removed by mechanical or chemical methodsafter composite manufacture.

The resultant composite may have features including: a premixed ormechanically blended diamond/metallic interface to reduce residualstress, a PCD surface that is the negative of the substrate, and lowresidual contamination in the diamond and metal carbide particles to bemoved to the bottom of the post-sintered PCD substrate. The catalystflow (sweep) occurs through the diamond layer, causing a physical actionthat in essence mechanically bonds and blends the interface layer andsubstrate particle bed during processing. The catalyst sweeps from thesubstrate toward the sacrificial substrate, thus pushing the impuritiestoward the PCD layer/sacrificial substrate interface and allowing muchof the impurities to be removed while sacrificial substrate is removed.

The present invention addresses manufacturing issues with current PDCcutters and inserts fabrication by including:

-   -   A less stringent requirement for diamond particle purity.    -   EB or vacuum brazed sealing of can/container may be used to        lower contamination levels prior to HTHP sintering to inhibit        impurity migration to the PCD surface.    -   Lapping of wear element face to remove PCD material that may        have a higher impurity concentration levels (Blemish) due to the        catalyst melt flow and surface interaction with the diamond        particles.    -   The post HTHP toughness/wear resistance of the sintered        substrate that is used as the catalyst source is controlled by        selection of in-situ sintered substrate grain size.    -   The infiltration rate and direction of catalyst is limited by        the sintered particle size and volume % binder in the cemented        carbide substrate.    -   The texture of the PCD working surface limited to the can        geometry.    -   Protrusions with hills or valleys on the tool faces for        aggressive cutting are difficult to form with the prior art cell        configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view of a typical drill rig in operation.

FIG. 2 is a view of a PCD cutting element typical for those of thepresent invention.

FIG. 3 is a perspective view drill bit which may utilize the PCD cuttingelements of the present invention.

FIG. 4 is a modified cross section view of a prior art PCD cuttingelement in a can ready for HTHP processing.

FIG. 5 is a perspective view of one embodiment of a PCD cutting elementof the present invention in a suitable can and ready for HTHPprocessing.

FIG. 6A shows one preferred non-planar interface pattern on asacrificial substrate used to make a PDC cutting element of the presentinvention and FIG. 6B shows a perspective view of the pattern as it isformed on the finished cutter.

FIG. 7A shows another preferred non-planar interface pattern on asacrificial substrate for a PDC cutting element in the presentinvention, and FIG. 7B shows a perspective view of the pattern as it isformed on the resulting cutter interface.

FIG. 8A shows still another preferred non-planar interface pattern on asacrificial substrate for a PDC cutting element in the presentinvention, and FIG. 8B shows a perspective view of the pattern as it isformed on the resulting cutter interface.

FIG. 9 is a cross section view a PDC element of the present inventionafter HTHP processing and before finishing.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, it is understood that the compositedescribed hereafter as formed of polycrystalline diamond, PCD, orsintered diamond as the material is often referred to in the industry,but can also be any of the super hard abrasive materials, including, butnot limited to, synthetic or natural diamond, cubic boron nitride, andrelated materials.

Polycrystalline diamond cutters are well known and used as cuttingelements in drilling bits used to form boreholes into the earth, and areprimarily used for, but not limited to, drilling tools for explorationand production of hydrocarbon minerals from the earth.

For illustrative purposes only, a typical drilling operation is shown inFIG. 1. FIG. 1 shows in schematic form a representation of a drillstring 2 suspended by a derrick 4 for drilling a borehole 6 into theearth for minerals exploration and recovery, and in particularpetroleum. A bottom-hole assembly (BHA) 8 is located at the bottom ofthe borehole 6. Oftentimes, the BHA 8 may have a downhole drilling motor9 to rotate an earth boring drill bit 1.

As the drill bit 1 is rotated from the surface or by the downhole motor9, it drills into the earth allowing the drill string 2 to advance,forming the borehole 6. For the purpose of understanding how thesesystems may be operated, for the type of drilling system illustrated inFIG. 1, the drill bit 1 may be any one of numerous types well known tothose skilled in the oil and gas exploration business. This is just oneof many types and configurations of bottom hole assemblies 8, however,and is shown only for illustration. There are numerous arrangements andequipment configurations possible for use for drilling boreholes intothe earth, and the present disclosure is not limited to the particularconfigurations as described herein.

As illustrated in FIG. 4, a cross section view of a prior art cuttingelement 50 is typically made up of only a polycrystalline diamond table55 integrally formed with a substrate 60 of tungsten carbide-cobalt (orother suitable hard metallic material). There are numerous knownvariations in configurations, sizes, shapes and materials for theseprior art cutting elements 50.

A more detailed view of the earth boring drill bit 1 that may use thecutting elements 10 of the present invention is shown in FIG. 3.Referring now to FIGS. 2 and 3, a superhard composite materialpolycrystalline diamond cutting element 10 of the present invention maybe a preform cutting element 10 for a fixed cutter rotary drill bit 1(as shown in FIG. 3). The bit body 14 of the drill bit may be formedwith a plurality of blades 16 extending generally outwardly away fromthe central longitudinal axis of rotation 18 of the drill bit. Spacedapart side-by-side along the leading face 20 of each blade 16 are aplurality of the PCD cutting elements 10 of the present invention.

A typical PCD cutting element 10 may have a body in the form of acircular tablet having a thin front facing table 22 of diamond bonded ina high-pressure high-temperature press to a substrate 24 of less hardmaterial such as cemented tungsten carbide or other metallic material.The cutting element 10 may be preformed as will be described in detailand then may be bonded on a generally cylindrical carrier 26 which mayalso be formed from cemented tungsten carbide, or it may alternativelybe attached directly to the blade 16. The PCD cutting element 10 hasperipheral and end working surfaces 28, 30 which, as illustrated, aresubstantially perpendicular to one another.

When a cylindrical carrier 26 is utilized, it may be received within acorrespondingly shaped socket or recess in the blade 16. The carrier 26may be brazed, shrink fit or press fit into the socket (not shown) in adrill bit 12. Where brazed, the braze joint may extend over the carrier26 and part of the substrate 24. In operation the fixed cutter drill bit12 is rotated and weight is applied. This forces the cutting elements 10into the earth being drilled, effecting a cutting and/or drillingaction.

These cutting elements 10 are typically made in a very high temperatureand high pressure pressing operation (which is well known in theindustry) and then finished machined into the cylindrical shapes shown.

The typical process for making these PCD cutting elements 10 typicallyinvolves combining mixtures of various sized diamond crystals, which aremixed together, and processed into the PDC elements 10 as previouslydescribed.

In various embodiments of the invention, a superhard composite materialcomprises a polycrystalline diamond cutter (PDC) having a flat cuttingsurface having a polycrystalline diamond thickness ranging from about 1to 5 mm or greater—but typically about 3 mm and a high-temperature,high-pressure (HTHP) in-situ cemented carbide substrate of about 10 mmthickness that is integrally formed with the PCD.

These PDC cutting elements 10 may be made in a manufacturing processwith a preformed can 100 that has at the bottom 112 a material forming abase substrate 104. An in-situ high-temperature, high-pressuresacrificial substrate 110 may be placed on top of the base substrate104. In a preferred embodiment the base substrate 104 may be domedwhereby the thickness at the center is much greater than the thicknessat the sides, as shown in FIG. 9. On top of the base substrate 104 maybe a layer of fine PCD diamond material 108 which may typically having arange of particle sizes. This diamond layer 108 will fill the can 100 toa level higher than the in-situ substrate 106. Because the in-situsubstrate 106 may be domed shaped, (as shown by numeral 114 in FIG. 9)the thickness of the diamond layer 108 will be less at the center thanat the periphery (as shown). A generally cylindrical sacrificialsubstrate 110 may be placed on top of the diamond layer 108. Thereaftera lid 112 placed upon the preformed can 100. The can 100 with the abovedescribed mixture is then processed to remove impurities; the can 100may be welded or otherwise hermetically sealed, and then subjected to ahigh pressure, high temperature process as is well known in theindustry.

What results is a superhard composite material that has a base substrate104 and a sacrificial substrate 110 that allows simultaneousinfiltration of the diamond layer 108 from both the top and the bottom.This process moves the impurities that tend to be pushed ahead of theliquid front as the sintering process proceeds toward the center of thesintered diamond material 108, instead of accumulating at the workingsurfaces, as is the case in prior art PDC elements.

The sacrificial substrate 110 may have various geometrical surfaceconfigurations, as shown in FIGS. 120A, 122A, and 124A. Although onlythree geometrical arrangements are shown, it is understood that a greatvariety of specific geometrical patters may be useful, and the presentinvention is not intended to be limited only to those shown. When thePDC elements are formed with these sacrificial substrates, a negative(or mirror image) of the pattern forms in the PCD layer 108 as the PDCelements is being formed in the HTHP process.

In the three specific geometries of the sacrificial substrates, asrepresented in perspective views by numeral 120A in FIG. 6A, 122A inFIG. 7A, and 124A in FIG. 8A, it can be seen that a negative pattern ofthe non-planar surface geometry will produced on the working surface ofthe finished cutting as shown in the perspective views of finishedcutters 120B, 122B and 124B in FIGS. 6B, 7B, and 8B. These cuttingelements 120B, 122B and 124B of the present invention have thegeometrical patterns that were formed by the patterns on the sacrificialsubstrate material 110. Even though the sacrificial substrate 110 isremoved (that is why it is called sacrificial) during processing, anegative of the pattern is left behind of the finished cutting element,as shown in perspective in FIGS. 6B, 7B and 8B.

The end result is a new type of PDC cutting element 10 with superiorphysical/mechanical properties as compared to the prior art.Furthermore, various geometrical patterns may be integrally formed onthe face of the cutting element in the formation process, providing anintegrally formed surface geometry on the ‘as pressed’ cutter—yielding aPDC cutting element with superior physical and mechanical properties.

As part of the manufacturing process, another advantage of the superhardcomposite material described above is that it may further utilize a can100 with a lid 112 for the HTHP component assembly with a shrink factorof about 1.10 for minimal OD grinding.

The superhard composite material may have a cobalt catalyst fordiamond-diamond particle sintering aid and WC-WC cementation is suppliedby a sacrificial cemented carbide substrate (as will be described indetail) that may have an average grain size of 20 μm and cobalt of 35Wt. %, and the finished cutter may be about 1613 mm in diameter.

Also, the sacrificial substrate 110 in contact with the diamondparticles may form a conic bevel at an outside diameter to form anin-situ chamfer on the PCD after HTHP processing, and further, thediamond feed stock may have a mono modal size of about 50 μm.Furthermore, a transition Diamond—WC-Co layer is formed by using aprobing tool that is used to selectively transfer WC-Co particle intothe diamond particle bed to a depth of about 1 mm. The can 100 and lid112 may be mechanically sealed and the can 100 is exposed to a HTHPprocess to enable composite densification aided via a catalystinfiltration from the cemented carbide substrate into the diamond andWC-Coparticle bed. The cemented carbide substrate is a sacrificialsubstrate, and the HTHP processing may require at least 40 k barpressures and a temperature of at least 1000° C.

The sweep or movement of the catalyst during HTHP processing may occurfrom the top of the PCD surface to the bottom of the in-situ formedsubstrate and after HTHP processing, the super hard composite isfinished by removal of the can 100 and substrate 110 and OD grinding.

The sacrificial substrate 110 may be separately formed of a metalcarbide selected from the group including a tungsten carbide, titaniumcarbide, tantalum carbide, and mixtures thereof, and the sacrificialsubstrate 110 may be formed of a carbide from the group of IVB, VB, orVIB metals which is pressed and sintered in the presence of a binder ofcobalt, nickel, iron, and alloys thereof, and may further have:

-   -   an average carbide particle size greater than >3 μm,    -   a weight % of binder material >3%,    -   a binder of Co, Ni, or Fe with at least 5 wt % Co in the        sacrificial binder phase,

The WC may be replaced with MC comprising M=V, Mo, Ti, Ta) and mixesthereof with a WC content of at least 5 wt %, and also the sacrificialbinder substrate that has M, C, Co (Fe, Ni) a eutectic compositionforming 100% melt at the eutectic temperature; W-C—Co or W-C—Ni eutectictemperate is about 1270 degrees C. There may also be a surface textureof the sacrificial substrate 110 in contact with the diamond particlewhich has a surface texture on the substrate is the negative of thedesired roughness on the cutting element face, and, the texture isformed by pressing the grade mix or post sintered operations includinglaser, EDM or other methods for providing the texture.

The above superhard composite material may also have a texturesupporting chip breaker geometries used for milling and turning insertsto aid with chipping of formation, and may have diamond particles with amulti-modal size distribution for optimal packing with a size range of 1nm to 100 μm, and, the diamond particles have a carbon phase additive >5wt % that is amorphous or nano structure fullerenes.

In addition, the superhard composite may have diamond particles whichare replaced with CBN particles, and may further have a mixture ofDiamond and CBN particles with at least 0.5 wt % diamond particles withan interface, with the interface probing depth 100% of the PCD layerwith a low WC concentration near a sacrificial substrate 110 and a highconcentration near the WC-diamond interface.

The WC content in diamond particle bed ranges at the preformed interfaceranges from 1 wt % to 80 wt % and the Carbide particles are formed of ametal carbide selected from the group consisting of tungsten carbide,titanium carbide, tantalum carbide, and mixtures thereof from the groupof IVB, VB, or VIB metals, and comprising a multi modal particle sizedistribution for optimal packing with a size range of 1 nm to 100 μm.,at least 5 wt % of the particles may be >50 μm to ensure adequateerosion resistance of the HTHP in-situ formed substrate.

The diamond particles, interface and WC particle bed may be preformsmanufactured using a fugitive binder like PEG, mineral oil and methylcellulose to limit segregation during transfer to the can 100, where amoldable diamond mix is pressed in the can 100 to conform to thesacrificial substrate 110 texture, an interface is formed by using aprobing tool to transfer a given amount of WC mix into the diamond mix,a WC mix is pressed into the can 100 above the interface, and, thefugitive binder is removed in the presence of hydrogen.

The superhard composite may also have a sink for a catalyst abridgingthe WC bed to reduce catalyst content in the densified PCD/substratewhere the sink comprises loose Zirconia ceramic particles and the like,that have greater resistance to HTHP sintering than WC particles in thepresence of the catalyst, and wherein the sink is removed after HTHPprocessing via a EDM, laser or abrasive cutting and furthermore,substrate removal may be by a mechanical dry/wet abrasives grinding orchemical leaching or a combination of both methods.

The PCD face may be coated with a nano coating diamond or diamond likecoating, and the cutter shape may have an irregular cross section, or anasymmetric cross section such as an oval, triangular, or a trapezoidalshape.

Furthermore, described herein is a superhard composite material having apolycrystalline diamond material comprising a generally flat cuttingsurface of a polycrystalline diamond material and having a thickness ofabout 3 mm further comprising a high-temperature, high-pressure (HTHP)in-situ cemented carbide substrate integrally bonded to the PCD.

The material may also comprise a can 100 and a lid 112 for the HTHPcomponent assembly with a shrink factor of about 1.10 for minimal ODgrinding, and have a cobalt catalyst for Diamond-Diamond particlesintering and WC-WC cementation that is supplied by a sacrificialcemented carbide substrate with an average grain size of 20 μm andcobalt of 35 wt. %.

The finished cutter described above may be about 1613 mm in diameter,and have a the sacrificial substrate 110 in contact with the diamondparticle forms a conic bevel at an outside diameter to form an in-situchamfer on the PCD after HTHP processing.

In addition, the diamond feed stock is a mono modal size of about 50 μmand the WC particle size in contact with the diamond particle may be amono modal size of about 50 μm.

The superhard composite material may have a transition Diamond—WC layeris formed by using a probing tool that is used to selectively transferWC particle into the diamond particle bed to a depth of about 1 mm, andbe processed in a can 100 and lid 112 which are mechanically sealed.

During processing, the can 100 may be exposed to a HTHP process toenable composite densification aided via a catalyst infiltration fromthe cemented carbide substrate into the diamond and WC particle bed, sothat the cemented carbide substrate acts as a sacrificial substrate 110,and the HTHP processing requires at least 40 kbar pressures and atemperature of at least 1000° C.

The sweep or movement of the catalyst during HTHP processing may flowfrom the top of the PCD surface to the bottom of the insitu formedsubstrate.

The sacrificial substrate 110 may be formed of a metal carbide selectedfrom the group consisting of a tungsten carbide, titanium carbide,tantalum carbide, and mixtures thereof or it may be formed of a carbidefrom the group of IVB, VB, or VIB metals which is pressed and sinteredin the presence of a binder of cobalt, nickel, iron, and alloys thereof,and may further have:

-   -   an average carbide particle size greater than >3 μm,    -   a weight of binder >3%,    -   the binder containing Co, Ni, or Fe with at least 5 wt % Co in        the sacrificial binder phase. The WC may be replaced with MC        comprising M=V, Mo, Ti, Ta (and mixes thereof) with a WC content        of at least 5 wt %.

The sacrificial binder substrate may also form a M, C, Co (Fe, Ni), aeutectic composition forming 100% melt at the eutectic temperature; theW, C, Co—Ni eutectic temperate is about 1270 degrees C.

The surface texture of the sacrificial substrate 110 in contact with thediamond particle may form a surface texture on the substrate is thenegative of the desired roughness on the cutting element face, and thetexture may be formed by pressing the grade mix or post sinteredoperations including laser, EDM or other methods for providing thetexture.

The texture may have incorporated within it chip breaker geometries usedfor milling and turning inserts to aid with chipping of formation, andthe diamond particles may have a multi-modal size distribution foroptimal packing with a size range of 1 nm to 100 μm, and the diamondparticles have a carbon phase additive >5 wt % that is amorphous or nanostructure fullerenes.

The diamond particles may be replaced with CBN particles or may be amixture of Diamond and CBN particles comprising at least 0.5 wt %diamond particles. The interface probing depth may be 100% of the PCDlayer with a low WC concentration near the sacrificial substrate 110 andwith a high concentration near the WC-diamond interface.

The WC content in diamond particle bed ranges at the preformed interfaceranges from 1 wt % to 80 wt %, and the Carbide particles may bee formedof a metal carbide selected from the group consisting of tungstencarbide, titanium carbide, tantalum carbide, and mixtures thereof fromthe group of IVB, VB, or VIB metals, and further have a multi modalparticle size distribution for optimal packing with a size range of 1 nmto 100 μm. At least 5 wt % of the particles are >50 μm to ensureadequate erosion resistance of the HTHP in-situ formed substrate.

The superhard composite may have the diamond particles, interface and WCparticle bed as made as performs, manufactured using a fugitive binderlike PEG, mineral oil and methyl cellulose to limit segregation duringtransfer to the can, so that a moldable diamond mix may be pressed inthe can to conform to the sacrificial substrate 110 texture, and aninterface is formed by using a probing tool to transfer a given amountof WC mix into the diamond mix and a WC mix is pressed into the canabove the interface, and then the fugitive binder is removed in thepresence of hydrogen.

The superhard composite may also have a sink for a catalyst abridgingthe WC bed to reduce catalyst content in the densified PCD/substratesuch that the sink has loose Zirconia ceramic particles and/or the like,that have greater resistance to HTHP sintering than WC particles in thepresence of the catalyst, and the sink is removed after HTHP processingvia a EDM, laser or abrasive cutting.

The substrate may be removed from the superhard composite by amechanical dry/wet abrasives grinding or chemical leaching or acombination of both methods, and furthermore, the PCD face of thecomposite may be coated with a nano coating diamond or diamond likecoating. The cutter shapes may include those with an irregular crosssection or symmetric cross section, such as an oval, triangular, or atrapezoidal shape.

Finally, the superhard composite may also form a composite tool with atypical geometry for cutting and milling inserts, or, it may have atypical geometry of inserts used for rolling cutter earth boring drillbits.

Whereas the present invention has been described in particular relationto the drawings attached hereto, it should be understood that other andfurther modifications apart from those shown or suggested herein, may bemade within the scope and spirit of the present invention.

1. A superhard composite material comprising a polycrystalline diamondcutting element comprising a cutting surface with a finishedpolycrystalline diamond thickness of between about 2 mm and about 5 mmand comprising a high-temperature, high-pressure in-situ formed cementedcarbide substrate that is integrally bonded to the PCD.
 2. The superhardcomposite material of claim 1 further comprising a can and a lid for theHTHP component assembly with a shrink factor of about 1.10 for minimalOD grinding, and the thickness of the in-situ formed cemented carbidesubstrate is between about 6 and 20 mm.
 3. The superhard compositematerial of claim 1 wherein a cobalt catalyst for Diamond-Diamondparticle sintering and WC-WC cementation is supplied by a sacrificialcemented carbide substrate with an average grain size of 20 μm andcobalt of 35 wt %.
 4. The superhard composite material of claim 3wherein the finished cutter is about 1613 mm in diameter.
 5. Thesuperhard composite material of claim 3 wherein the sacrificialsubstrate in contact with the diamond particle forms a conic bevel at anoutside diameter to form an in-situ chamfer on the PCD after HTHPprocessing.
 6. The superhard composite material of claim 5 wherein thediamond feed stock is a mono modal size of about 50μ.
 7. The superhardcomposite material of claim 5 wherein the WC particle size in contactwith the diamond particle is a mono modal size of about 50 μm.
 8. Thesuperhard composite material of claim 5 wherein a transition Diamond—WClayer is formed by using a probing tool that is used to selectivelytransfer WC particle into the diamond particle bed to a depth of about 1mm.
 9. The superhard composite material of claim 2 wherein the can andlid mechanically sealed.
 10. The superhard composite material of claim2, wherein the can is exposed to a HTHP process to enable compositedensification aided via a catalyst infiltration from the cementedcarbide substrate into the diamond and WC particle bed, wherein thecemented carbide substrate is a sacrificial substrate, and wherein theHTHP processing is at least 40 kbar pressures and the temperature is atleast 1000° C.
 11. The superhard composite material of claim 2, whereinthe sweep or movement of the catalyst during HTHP processing occurs fromthe top of the PCD surface to the bottom of the in-situ formedsubstrate.
 12. The superhard composite material of claim 11 whereinafter HTHP processing, the super hard composite is finished by removalof the can/sacrificial substrate and OD grinding.
 13. The superhardcomposite material of claim 11 wherein the sacrificial substrate isformed of a metal carbide selected from the group consisting of atungsten carbide, titanium carbide, tantalum carbide, and mixturesthereof.
 14. The superhard composite material of claim 13 wherein thesacrificial substrate is formed of a carbide from the group of IVB, VB,or VIB metals which is pressed and sintered in the presence of a binderof cobalt, nickel, iron, and alloys thereof, and further comprises: anaverage carbide particle size greater than >3 μm, a weight % Binder >3,a binder comprising Co, Ni, or Fe with at least 5 wt % Co in thesacrificial binder phase.
 15. The superhard composite material of claim14 wherein WC is replaced with MC comprising M=V, Mo, Ti, Ta) and mixesthereof with a WC content of at least 5 wt %.
 16. The superhardcomposite of claim 15 wherein the sacrificial binder substrate that hasM, C, Co (Fe, Ni) a eutectic composition forming 100% melt at theeutectic temperature; W, C, Co—Ni eutectic temperate is about 1270degrees C.
 17. The superhard composite material of claim 1 wherein asurface texture of the sacrificial substrate in contact with the diamondparticle comprises: a surface texture on the substrate is the negativeof the desired roughness on the cutting element face, and the texture isformed by pressing the grade mix or post sintered operations includinglaser, EDM or other methods for providing the texture.
 18. The superhardcomposite material of claim 17 wherein the texture can have chip breakergeometries used for milling and turning inserts to aid with chipping offormation.
 19. The superhard composite of claim 1 wherein the Diamondparticles have a multi-modal size distribution for optimal packing witha size range of 1 nm to 100 μm, and the diamond particles have a carbonphase additive >5 wt % that is amorphous or nano structure fullerenes.20. The superhard composite of claim 19 wherein the diamond particlesare replaced with CBN particles.
 21. The superhard composite of claim 20further comprising a mixture of Diamond and CBN particles comprising atleast 0.5 wt % diamond particles.
 22. The superhard composite of claim 1wherein the interface probing depth may be 100% of the PCD layer with alow WC concentration near a sacrificial substrate and a highconcentration near the WC-diamond interface.
 23. The superhard compositeof claim 1 wherein the WC content in diamond particle bed ranges at thepreformed interface ranges from 1 wt % to 80 wt %.
 24. The superhardcomposite of claim 1 wherein the Carbide particles are formed of a metalcarbide selected from the group consisting of tungsten carbide, titaniumcarbide, tantalum carbide, and mixtures thereof from the group of IVB,VB, or VIB metals, and comprising a multi modal particle sizedistribution for optimal packing with a size range of 1 nm to 100 μm,wherein at least 5 wt % of the particles are >50 μm to ensure adequateerosion resistance of the HTHP in-situ formed substrate.
 25. Thesuperhard composite of claim 1 wherein the diamond particles, interfaceand WC particle bed are preforms manufactured using a fugitive binderlike PEG, mineral oil and methyl cellulose to limit segregation duringtransfer to the can, wherein, a moldable diamond mix is pressed in thecan to conform to the sacrificial substrate texture, an interface isformed by using a probing tool to transfer a given amount of WC mix intothe diamond mix, a WC mix is pressed into the can above the interface,and the fugitive binder is removed in the presence of hydrogen.
 26. Thesuperhard composite of claim 1 comprising a sink for a catalystabridging the WC bed to reduce catalyst content in the densifiedPCD/substrate wherein the sink comprises loose Zirconia ceramicparticles and the like, that have greater resistance to HTHP sinteringthan WC particles in the presence of said catalyst, and wherein the sinkis removed after HTHP processing via a EDM, laser or abrasive cutting.27. The superhard composite of claim 1 wherein substrate removal is by amechanical dry/wet abrasives grinding or chemical leaching or acombination of both methods.
 28. The superhard composite of claim 1wherein the PCD face is coated with a nano coating diamond or diamondlike coating.
 29. The superhard composite of claim 1 wherein that thesaid cutter shape has a irregular cross section or symmetric crosssection such as an oval, triangular, or a trapezoidal shape.
 30. Thesuperhard composite of claim 1 wherein the composite tool has a typicalgeometry for cutting and milling inserts.
 31. The superhard composite ofclaim 1 wherein the composite tool has a typical geometry of insertsused for rolling cutter earth boring drill bits.